Assiguqb to the eiv- ull-pabkeb



15,497. s SHEETS-SHEET 1.

w B 6M1 Wham;

vC. E. COCHRAN. INDUSTRIAL TRUCK.

I I I lul HHK APPLICATION FILED FEB. 24,1919,

Reissged N -c. E. COCHRAN. INDUSTRIAL TRUCK.

AHLICATION FILED FEB 24. 1918.

15,497. 3 SHEEISSHEET 2.

9 2 9 1 8 2 w N m v3 mu c E. COCHRAN. INDUSTRIAL TRUCK.

APPLICATION FILED FEB. 24.1919.

' a SHEETS-SHEET a.

keissued Nov. 28, 1922.-

I J3 I 44 4:

Reissued Nov. 28, 1922 UNITED STATES Original 1,260,145,

To all w ham/it may concern:

Be it known that I, CLYDE E. Co'oHnAN, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement inan Industrial Truck, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to automobile trucks, which, in addition to the frame, supporting wheels and propelling mechanism have suitable means carried by the frame for shifting a load relatively to it, enabling the load to be conveniently picked up and shifted into )osition for transportation by the truck, and thereafter deposited in a'desired new location. Such trucks, are of great use in factories, warehouses, freight stations, etc., for handling goods with the minimum of manual assistance.

The object of this invention is to provide a simple, effective and powerful mechanism adapted to be mounted on the truck frame and manipulate the load. This mechanism comprisesa load engaging member movably carried by the truck frame, a longitudinally movable rod for operating it, a screw and nut couple for moving the rod, and an operating motor. Preferably the rod carries the screw thread which is engaged by the nut, and the latter preferably carries worm teeth meshing with a worm driven directly by the armature shaft of the motor. The motor, gearing, nut and screw are all mounted to swing as a unit about a horizontal axis so that these parts may accommodate themselves to various directions of the rod corresponding to various positions of the load shifting mechanism.

The mechanism which -engages and supports the load will be varied according to the character of load to be picked up, and transported, and may include a linkage system connecting the load carrier with the truck frame, which system would also be varied according to the movement desired for the load engaging mechanism.

One einbodimentof the invention which has been found very useful is where the loadengaging mechanism is a horizontal platform adapted to be elevated to engage a load which has been so supported that the truck may back the platform beneath I Re. 15,497 PATENT OFFICE.

CLYDE E. GOCHRAN, 0F CLEVELAND, OHIO, ASSIGNOR TO THE E113?-ElLL-PAItKIER ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION u)! OHIO.

INDUSTRIAL TRUCK.

it. In this case the preferred linkage system includes inclined links connecting the horizontal platform with the truck frame dated March 19, 1918, Serial No. 130,518, fileii November 10, 1916. Application for reissue filed February 24, 1919. Serial No. 278,999.

so that a. pull on the end of the platform will cause it torise. a

The drawings illustrate my invention enibodied in a truck having a horizontal vertically-raisable platform. In these drawings, 1 is a side elevation; Fig. 2 is a. plan; Fig. 3 is a view in the nature of a plan 011 an enlarged scale of the motor and mechanism. connecting it to the platform; Fig. 4 is a section through the worm wheel and the worm with the motor shown in side elevation; Figxfi is a section along the axis of the screw which elevates the platform,

showing the motor in end elevation; Fig.

6 is an elevation ofthe brake mechanism, looking toward the end of the motor casing; Fig. 7 is a sectional side elevation of the brake mechanism looking from the oppositedirection of Fig. 4:.

Referring briefly to the general construction shown, 1 indicates a front housing carrying a driving motor indicated at 2, and a battery therefor in a suitable box 3. Extending rearwardly from the lower portion of this front housing is a low lying skeleton franie 10. Suitably mounted on the sides of the housing are the propelling wheels 20, and carried by the rear frame are the wheels 21. The driving motor is suitably connected with the propelling wheels 20 in any well known manner; thus the motor maybe connected by worm gearing (not shown) in the casing 4 with the rotary axles of the wheels. .The motor is controlled b a suitable controller indicated at 6, whic is provided with an operating handle 7. The steering may be accomplished in any desired manner. a or example, all four wheels may be steered, the wheels bein shown in Fig. 2 as connected by a system 0 cross links 24 and 25, and longitudinal links 26 and 27, with a steering column 28 (Fig. 1) operatedby a hand lever 29.

It is to be understood that the general construction just described may be altered edges of the platform, and may conveniently 1 he channel 'heams. as shown. The fronthousing has other uprights l3 and 16 secured at their lower ends to extensions 17 of the sill frame. The sill frame is completed by pads 18 and 19 rigidly onnected with the uprights 11 and 13. The housing also has two uprights 14 of channel shape secured to the outer sides of the sills l and rising vertically at the rear end of the housing. All of the uprights are secured to the horizontal flanged plate which carries the battery box. A vertical plate 16 forms a rear wall for the housing and is secured to the 11prights let. i

The arrangement described. ot' sills. nprights 11 and 1.3. and cross pads lb and ll).

provides a box-like space in which the front axle may rise and tall; The frame is preferablv supported by springs :23, between the pads d! and thc floating casing :22 of the axlcfialter the manner oi a journal box o a railway car. The motor rises and falls withlhe axle. being connected with it by the gear casing -l and-also by a brace 5 leading upwardly from the axle and connected at the upper end by a bracket 8 to the motor casing. This driving connection is simple. direct. and compact. and the spring suspeusion relieves the truck. and its load. of gars.

The raisahlc platform. which constitutes the loadfeng: g'ing member inthis particular enilaidinleiit. is shown in Figs. 1 and 2 and designated 30. This platform is a horizontal member connected with the sill structure by parallel Links 31 and 32. There are two links Ill on the outer sides of the sills i and pivoted at their lower ends to brackets 33 which are secured to the sills and to the rear end of the trout housing; The upper ends of these links are pivoted to brackets 34- Sccured to the under l'acc ot' the platform. Atthe rear l prefer to employ one link 3:2 which is mounted centrally bethe sills and pivoted at its lower end is. and at its upper end to-thc under side of the platl'orm. These links, I31 and .312 are shown as webbed for strength. They are of th same length and are parallel. so

that as no platform moves it rcu'iains alwav. horicon'tal. moving upwardly and to 'l l. aro lil.

Front as it rises and dowuwardl) rill it is lowered. go ng and screw 'l'or clcvatuplat form are carried within the housin tin pa e immediately in troutol" upr g il llllh'lh H; and beneath the sup-.

lower ends to onc t of posts 1 l. Mounted on thesidiagonal bars 4-0 are bearing brackets ll. into these brackets extend ingly. I prefer to make the casing for the worm wheel and nutin two parts. The, main portion 46 ot' the worm wheel casing ma conveniently be integral with the casing 47 for the worm. and with the casing 43. for that portion of the screw between the nut and platform. as shown in Fig. The projecting end of the screw is housed by a tubular casing which extends from a plate in which is bolted to the casing all Suitable webs are provided to strengthen and stiffen the parts ofthe casing which as shown may conveniently be made by two castings. The trnnnions 42 may be studs screwed into the casing 43.

The screw 50 is shown clearly in Fig. 5. It lies within the casings 43 and 45 and has a shank 53 extending out through a stulling box 5411f the lower end of the cas ing. This shank is provided at its lower end with a head 56 which is connected by a pivot pin 51 with a bracket 58 secured to the l'orward end of the elevating platform an. llithin the casing 46 and threaded on the screw is a nut. 60 which is shown as taking its thrust against a ball bearing (51 in the casing. 'lhis nut carries at its outer edge teeth of a worm wheel. 'lhcsetccth are on a ring 6:2 scparatelrom the body of the out but connected. with it by a friction clamp consisting of a flange (i-l on the nut and a ring (35. bolts (it; and nuts (it-L and in (l7 compressed between the bodvot the nut (30 and the nuts (38. By these means Hul licicnt friction is maintained at the clamp' so that normally the worm lccth and the nut revolve as a unit. but slippage is possi ble in case of an excessive load on the platform or other abnormal condition. The separation of the teeth and body of the worm wheel'also allows the teeth to be made of bronze and the body of steel. which is an ulvant-age.

The worm for driving the worm whccl described is designated 69. It mounted in the casing 47. and meshes with the worm teeth (32. and is connected to the shaft of the armature. As shown in Fig. 1-,. the thrust of the worm is taken in either direc .tion by a double ball bearing (38. mounted n the end of the worm casing 47. The other end of the worm [8 connected by a suitable. coupling to the armature shaft 81. .This

coupling is shown as consisting of a square extension on the armature shaft engaging a corresponding recess in the worm,

It will be seen from the above construction that when the armature is revolved. the. worm causes the nut to revolve comparatively slowly, which more slowly pulls up on the screw shaft to elevate the platform. Oil for the worm gearing and for the nut and screw are contained within the hollow casing. being retained therein by the studing box 54.

In the operation of the truck shown. it is usually backed to bring the platform under the goods to be carried; then the raising motor is operated, which, through the gearing. nut and screw described, draws up on the. shank 53 and elevates the platform, swinging it upwardly and forwardly until the load is picked up: then the truck is driven to the desired position with the load in this condition, after which the motor -19 is reversed and the platform is lowered to is on.

allow the load to descend onto a suitable support. The-speed of the armature is preferably such that the load is quickly raised, the reduction in the gearing giving the requisite power.

Any suitable means may be employed to open the circuit to the raising motor automatically when the platform reaches its uppermost or lowermost position. thus preventing the motor driving too far. The slip connection in the worm wheel also protects the mechanism. As an additional protection I provide a magnetic brake which is held in idle position when-the current is flowing through the raising motor. but is automatically seated by spring action wheni ever the current is interrupted. Accordingly, whenever the currcntfis off the brake As the current is automatically broken at the extreme positions of the platform, the operation of the raising motor is immediately stopped at thesc positions. The brake is located on the end of the motor casing opposite to the worm drive, and is shown particularly in Figs. 6 and T and will now be described) Secured directly to the end of the motor casing is a housing formed with an annular recess to accommodate an annular winding 71 which is in series with the motor. The annular portions of the housing on opposite 'sides' of this winding form north and south poles of a magnet; 74'indicates a ring-like piece of' metal which constitutes an armature for the magnet described. This armature is normally held distant from the magnet by means of springs 76- mounted, inrecesses in the housing and bearing against the armature ring. Suitable studs T7 ca rricd by-the housing guide the. ring. Secured at intervals on the ring are segmental linings T8 of suitable braking substance.

The springs 76 tend to press the armature ring with the linings outwardly into contact with a disk 80' secured .to the end of the armature shaft. This disk lies within a flange 79 of the housing 70. Normally the brake is held active by the springs 7%, preventing the armature revolving and thus holding the platforn'i in a definite position. When, however, the current is turned into the raising motor the winding 71 is energized and the armature H is drawn inwardly away from the disk SO'and this disk freed.

Having thus described my invention, what I claim is: i

1. In an industrial truck, the combination of a front housing, a rearwardly extending 'sillframe, a movable load carrier, mounted on the sill frame, an electric motor,a connection between said motor and the load carrier, including a nut and screw, one geared with the armature shaft and the other con nected to the load carrier, and a pivotal sup-' port for the motor, nut and screw, pivoted to the front housing between the motor and load carrier. whereby the weight of the motor may act as a counter balance.

2. In a truck of the character described, the combination of a truck franie. a. hollow casing carried by the truck frame, a screw and nut occupying the casing, the screw having a shank extending outside of the casing, load operating mechanism mounted on the truck frame and connected with said shank, worm wheel teeth carried by the nut, a worm meshing with said teeth. aiid an electric motor the armature of which is connected with the worm, the casing described being separable. one part carrying-a housing for a portion of the screw and for a part of the worm wheel and the worm. and the other part forming a portion of the worm wheel housing and having an extension forming a.

with the frame, a longitiulinally movable rod adapted to move the load-supporting device. a screw on said rod. a nut for the screw, a worm wheel connected with the nut, a worm engaging the worm wheel, an electric motor having its armature shaft coupled with the worm, and an oscillating frame carrying the motor. the gearing. and the nut,

In a truck, the combination with a frame. of 11 load reeeiring platform mounted thereon. suid Pltlt'lOlIll being adapted to move upwardly, a motor for operating said platform. a couple comprising two interen gaging members. one of said members being associated with the plz ttortn and the other being; connected with the motor, and an oscilluting t'rnine carried by the truck frame and ph pted' thereto intermediate the motor and the platform. j

G. In in truck, the combination of a frame, a movable load carrier carried thereby, ascrew connected with the load carrierganut for the screw carrying Worm teeth, frictionnlly secured thereon, an electric motor, a Worm meshing with the worm teeth and connected to the armature shaft of the motor, and a pivotnlly mounted easing carrying the nut, worn] and the motor.

7. In 11 truck. the combination of a housing provided with means for carrying a battery. :1 rearwardly extending frame, a loud carrier mounted on said frame, an elec' tric niotor located. within the housing heneath the battery and adapted to be driven thereby, a nutgeared with the motor, a screw extending from the nut rearwardly and connected with the load carrier, and int-ans for pivotally mounting the motor, nut and. SQZ'QW. whereby they may swing as the load carrier mores.

The combination of a housing. a frame extending therefrom. a movable loud raising mechanism mounted on and adapted to extcnd above the extended portion of the frame. a casing pivotally carried in the housing. it screw within said fasing eonnected at its rear end to the said meehanism n nut within'the (fusing. engaging: the screw. an electric motor bodily Inovahle with the casing and gearing between the urn'iature shaft of the motor and the nut.

9. In an industrial truck. the combination oi :1 front housing a reurwnrdly extrmlin; sill frame therefrom. load raising mechanism carried by the extei'ision of the sill frame. a pair of hearings carried by the honsing. an oscillating hollow frame having: trunnions mounted in said hearings, a screw connected with the load raising niechzinisnn and extending into the hollow frame. a nut within the hollow frame on ,the screw. an ilertrir motor whose frame is rigidly connected with. the hollow frame to move therewith. and gearing & -)I1ll{(tl]lf the armature shaft of the motor with the nut.

to. in u truck of the character described.

the combination of :1 frame. r. load raising mechanism connected tnerewith. a hollow rinsing pixotully mounted. on the truck trznnc it screw. the outer end ot whirh is giiivotnllx' connertcd with the load raising. mechanism. l out for the scrcw. said casing having a cluunber tor the St wt. and a L7Ull1- innnlezrting chamber for the nut an electric motor mounted on the casing to move therewith, and gearing between the armature shaft of the motor and the nut.

11. In a truck 0t the character described, A the oon'ibination of a truck frame, loud Inanipuliiting mechanism carried thereby, a hollow easing pivotally carried by the truck frame a screw and nut occupying the easing, the screw having a shank extending outside of the casing and connected with said mechanism, worm Wheel teeth carried by the nut. a worm meshing with said teeth. and an electric motor the armature of which is connected with the worm, the casing described being separable, one part having trunnions whereby it is pivotnlly mounted and carrying a housing for a. portion of the screw and for a part of the worin wheel and the worm, and the other part forming a portion of the worm wheel housing and hem ing an extension forming" a cap over the pro jeetingr end of the screw.

12. In an industrial truck, the combinm tion of a fronthousing carrying a battery, a sill frame extending rearwnrdly from the housing. load manipulating mounted on the sill frame. a .pivotelly monnted casing within the housing. a nut within the casing. a screw extending from said nut out of the casing rearwnrdly and 'pivotzilly connected with the loud manipulating mechanism. and a motor adapted to rotate said nut 13 In a truck ofthe character described, the combination of a loud supporting" mechanism, a separable easing. having a tubular portion. :1 nut carrying worm wheel teeth mounted in the casing. a worm mounted in a communicating partiallytubular portion of said casing and meshing withsziid teeth an electric motor having its armature slum; connected with the worm. and 3V ser w oecupying the nut and extending out of the casing and pivotelly eonneeted with the load supporting mechanism. i 14. In a truck of the rharzzctcr described. the co1nl ination of a frame, load supporting mechanism. niovahly connected tl'ierewitln an oseillziting (using mounted on the frame. 2i nut in the casing. tin electric motor having; its frame rigidly connected with the easing and its arnu ture shutt geared with the nut. a srrew occupying the nut and extending: out. of the casing, and eounerted ,with the loud supporting nieelninisni. and 1-. stufiing box enrried h); the casing und surrounding the Hllilllliljf the serewi 15. The combination of a truck frame. loud supportingmechanism mounted thereon. a screw pivotslly mounted and c nl ertfid' with the loud su 'iporting mechanism, loud supporting mechanism being ed that the longitudinal mm the screw moves the loud supper nisrn and at the some ti D o mountineehani sin i on-its pivot, a nut for the screw, a motor geared with the nut, and an oscillating frame carried by the truck frame and carrying the screw, nut and motor, said oscillating frame being pivotally mounted between the nut, gear ng, and motor on one side, and the load supporting mechanism on the other.

16. In a truck, thecombination of a truck frame, a power raising mechanism pivotally mounted on the truck frame, such power raising mechanism comprising a screw and nut couple, and an electric motor geared with the rotary member of such couple, and load raising mechanism connected with the longi t; dinally moving member of the screw and nut couple and so mounted that the lon gitudinal movement of said member may move said ioad raising mechanism and at the same time rock said member onits pivot, said pivot being located between the motor,

gearing and nut on one side, and the load raising mechanism on the other, whereby the motor, gearing and nut, may act as a counter balance. 7

17. In a truck, the combination of a housing, a sill frame extending therefrom, a movable load carrier connected with the sill frame, a screw connected with the load carrier, a pivotally mounted casing carried by the housing into which the screw extends, a nut for the screw within the casing, an electric motor having its armature geared with the nut, said motor being carried by the carsing to move bodily, and a magnetic brake carried by the motor casing, and bodily movable therewith and adapted to stop the rotation of the armature.

18. In a truclt, the combination of a front housing, a rearwardly extending frame, a

bodily raisa'ble platform mounted above said frame, a motor carried by the housing for raising the platform, a screw extending from a point within the housing to the platform,

a nut within thehousing on the screw, gearing between the motor and the nut, and a casing pivctally mounted within the housing and enclosing the screw, nut and gearing, sai'C motor being mounted on said casing.

19. In an industrial truck, the combination bf a front housingga rearwardly extending sill frame, a raisable platform over the cxtension of the sill frame, a battery box frame, a screw and nut occupying the casing, the screw having a shank extending outside of the casing and connected with the platform, worm wheel teeth carried by the nut, a worm meshing with said teeth, and an electric motor the armature of which is connected with the worm, the casing described being separable, one part carrying a housing for a portion of the screw and for a partof the worm wheel and the worm, and the other part forming a portion of the worm wheel housingand having an extension forming a cap over the projecting end of the screw.

21. In a truck, the combination of a raisable platform, a nut and screw, one member of which is connected with the platform, a motor for driving the other member of such connection and an oscillatingdevice carried by the truck frame and completely enclosing the nut and screw, said screw having a shank adapted to extend through said device, said motor being mounted on said oscillating device, and means whereby relative movement between said nut and screw causes said platform to be moved longitudinally while being raised.

22. In a truck, the combination of a frame, load supporting, mechanism movably carried thereby, a motor raising mechanism between the motor and ioad supporting mechanism to enable the motor to elevate the load, and a pivotal support for the motor and raising mechanism, located between the motor and load supporting device whereby the motor may act as a counter balance.

23. The combination of a housi' r, a frame extending therefrom, a platform above the extended portion of the frame and connected therewith in a manner to cause it to rise when moved longitudinally, a casing pivot- "ally carried in. the housing, a screw Within said casing, connected at its rear end to the platform, a nut within the casing engag: ing the screw, a-motor bodily movable with the casing, and gearing between the armature shaft of the motor and the nut.

24. In an industrial truck,- the combina tion of a front housing, a-rearwardly extending sill frame therefrom a raisable platform carried above the extension of the sill frame, a pair of bearings carried by the housing, an oscillating hollow frame hav ng trunnions mounted in said bearings, a screw connected with the platform and extendlng into the hollowiframe, a nut within the hollow frame on the screw, an electric motor whose frame is rigidly connected with the hollow frame to move therew1th, and gear ing connecting the armature shaft of the motor with the nut. l

25. In a truck of the character described, the combination of a frame, a ralsable platform connected therewith, a hollow casing. pivotally mounted on the truck frame, v

screw, the lower end of which extendsi the nut.

26. In a truck of the character described,

v the combination of a truck frame. an elevating platform, parallel links connecting them,

a hollow casing pivot-ally carried by the truck frame, a screw and nut occupying the casingthe screw having a shank extending outside of the casing and connected with the platform, worm wheel teeth carried by the nut, a worm meshing with said teeth, and an electric motor the armature of which is connected with the worm, the casing described being separable, one part having trunnions whereby it is pivotally mounted and carrying a housing for a portion of the screw and for a part of the worm wheel and the worm, and the other part forming a portion of the worm wheel housing and having an extension forming a cap over the projecting end of the screw.

27. In an industrial truck. the combination of a front housing carrying a battery, a -sill franie extending rearwardly from the housing. araisable platform above the sill frame, parallel links connecting the platform with the sill frame, a pivotally mounted. casing within the housing, a nut within the casing, a. screw extending from said nut out of the casing diagonally downward and rearwardly and pivotally connected with the front end ofthe platform, and an electric motor adapted to rotate said nut.

1 28. In a truclnof the character described, the combination of a raisable platform, a separable casing, a not carrying worm-wheel teeth mounted in the casing, a worm mounted in a communicating casing and ineshing with said teeth, an electric motor having its armature shaft connected with the worm, a screw occupying the nut and extending out of the casing and pivotally connected with the platform, and a stulling box carried by the casing and surrounding the shank of the screw.

29. In a truck of the character described, the combination of a frame. a raisablc plat form movably connected therewith in a manner to cause its elevation when moved longitudinally, an oscillating casing. mount- ,ed on the frame, a nut in the casing, an

electricmotor having its frame rigidly conncctcd with, the casing and its armature shaft geared with the nut. a screw occupying'the nut and extending out of the casing, and connected with the platform, and a stufiing box carried by the casing and surrounding the shank of the screw.

casing carrying the nut,

30. In a truck, the combination of a frame, a raisable platform carried thereby, a screw connected with the platform, a nut tor the screw carrying'worm teeth. an electric motor, a worm meshing with the worm teeth and connected. to the armature shaft of the motor, and a pivotally mounted separable worm and the motor.

31. The combination with a truck frame, of a raisable platform, an oscillating frame, an electric motor. and suitablemechanism including a screw, both carried by said oscil lating frame and adapted to raise the platform, said oscillating frame being, pivoted between the motor and platform, and a brake for the armature of the motor bodily movable with the motor casing.

32. In a triui-k, the combination of a housing, a sill frame extending therefrom, a raisable platform connected with the sill frame, a screw connected with the platform,

-a pirotally mounted casing carried by. the

housing into which the screw extends, a out for the screw within the casing, an electric motor having its armature geared with the nut, said motor being carried by the casing to more bodily, and a magnetic brake -arried by the motor casing and bodily movable therewith and adapted to stop the rotation of the armature.

In a truck, a frame, a load receiving platform, movably mounted thereon and ar ranged to more upwardly, platform elevating means including a thrust rod adapted to move in one direction to elevate said platform and to more in an opposite direction to lower the platform, a motor, reduction gearing and a power transmitting couple, and means for pivotally supporting said couple, reduction gearing and motor on a transverse axis located between the motor and platform.

34. in a truck, aframe having a low rear extension. front and rear wheels supporting the frame. a load receiving platform above said extension, said platform being arrangedto more upwardly, while remaining parallel to its lowered position. platform elevating means including a thrust rod adapted to move in one direction to elevate said platform and tomovc in an opposite direction to lower the platform, an electric motor adjacent said thrust rod, a power transmitting rotaiycouple including a nut and screw be tween said motor and thrust rod, compactly arranged reduction gearing directly U0llnecting said motor and said couple, said reduction gearing consisting of meshing peripherally toothed rotary members, the driving member of which is mounted on the armature shaft of said motor and the driven member on the rotary element of the power transmitting couple, a. single gear box housing the reduction gearing, and means .for pivotally supporting the motor and gea'rin;: on a transverse axis between the motor and. platform; 35. In a trurk, the combination of a frame.

5 load supporting mechanism movably carried therebvv a motor and raisimg mechanism bonnet-ted with the motor and the load supporting" meehanism to enable the motor to elevate the load. said motor-and raising 10 merhnnism beingroupled together and supported us a unit on an intermediate horiizont'al pivot whereby they may act as a lever--01 the first class to partiall counter halan -e the load supporting mechanism.

36. In a truck,the combination of a frame, load supporting mechanism carried thereby, motor. raising mechanism includii'ig a screw and nut oouple geared with the motor and connected with the load supporting mechanism, said motor and raising mechanism being mounted in'jsueh manner that they may swing 'in a vertical plane about an intermediate axis and thereby partially counter balance the load supporting merliw nisln.

Signed at Cleveland, Ohio, this 21st day of February, 1919.

' CLYDE E. COCHRAN. 

